Integral box construction for steam generators



Oct. 19, 1965 s. F. MUMFORD ETAL 3,212,481

INTEGRAL BOX CONSTRUCTION FOR STEAM GENERATORS Filed July 21, 1964 4Sheets-Sheet 1 STEPHEN F. MUMFORD 36 34 RAMSEY U. SHEIKH FIG. 4

Oct. 19, 1965 s. F. MUMFORD ETAL 3,212,481

INTEGRAL BOX CONSTRUCTION FDR STEAM GENERATORS Filed July 21, 1964 4Sheets-Sheet 2 nnuvwnc 36 54 22x 28A 12Xj d STEPHEN F. MUMFORD RAMSEY U.SHEIKH g ramz MW awe/Mm:

Oct. 19, 1965 s. F. MUMFORD ETAL 3,

INTEGRAL BOX CONSTRUCTION FOR STEAM GENERATORS Filed July 21, 1964 4Sheets-Sheet 3 STEPHEN E MUMFORD RAMSEY U. SHEIKH 1965 s. F. MUMFORDETAL 3,212,481

INTEGRAL BOX CONSTRUCTION FOR STEAM GENERATORS 4 Sheets-Sheet 4 FiledJuly 21, 1964 FIG. 9

INVENTORS. STEPHEN F. MUMFORD RAMSEY U. SHEIKH ATTORNEY United StatesPatent 3,212,481 INTEGRAL BGX CONSTRUCTION FOR STEAM GENERATORS StephenF. Mumford, Bloomfield, Conn., and Ramsey U. Sheikh, Westhoro, Mass,assignors to Combustion Engineering, Inc., Windsor, Conn., a corporationof Delaware Filed July 21, 1964, Ser. No. 384,111 Claims. (Cl. 122510)This application is a continuation-in-part of US. patent applicationSerial No. 155,546, filed November 29, 1961, now abandoned.

This invention relates to vapor generators. More particularly, theinvention relates to an improved steam generating apparatus of integral,welded wall construction designed to accommodate steam loads in therange of 80,000 to 600,000 lbs. of steam per hour with steamtemperatures in the range of about 1000 F. and design pressures of about1600 psi.

In the construction of high capacity steam generators considerableexpense is realized in the time and effort expended in field erection ofindividual generator elements as well as in the cost of the materialsemployed in the construction of the generator. It is, therefore, anobject of the invention to provide a novel compact steam generatingapparatus utilizing standardized, shop-assembled components to themaximum extent possible so as to substantially reduce the time andeffort normally required for field erecting such units and to reduce thematerial costs of such structures.

Another object is to provide a high capacity steam generator that isbottom supported in such a manner as to require a minimum amount ofsupporting members. This is attained by providing a compact unit havingwalls in the form of integral tubular panels so arranged as to effectvertical thermal expansion and thereby eliminate the need for external,heavy steel supporting members. The utilization of welded wallconstruction throughout the unit in addition to the particulararrangement of the various elements so as to reduce the unsupportedlength of the walls obtains a rigid, box-like structure that renders theunit substantially self supporting.

A further object is to provide a high capacity steam generator that isselfencasing to the extent that the need for heavy skin casing or otherpressure sealing material is substantially eliminated. This is attainedby the utilization of welded tube construction throughout all theenclosing walls, roof and floor of the steam generator therebypermitting the tubular elements to serve as the pressure containmentstructure.

Various other objects and advantages will appear from the followingdescription of one embodiment of the invention, and the novel featureswill be particularly pointed out hereinafter in connection with theappended claims.

The invention is described with reference to the accompanying drawingswherein:

FIG. 1 is a sectional elevation of a steam generator constructed inaccordance with the instant invention;

FIGS. 2 and 3 are diagrammatic perspectives of the steam generator shownin FIG. 1;

FIG. 4 is a typical section through one of the walls of the steamgenerator;

FIG. 5 is a transverse section taken along line 55 in FIG. 1;

FIG. 6 is a partial plan view of the lower drum and supply tubes of thesteam generator;

FIG. 7 is a partial plan view of the upper drum and riser tubes of thesteam generator;

FIG. 8 is a plan view illustrating the arrangement of the floor supportsfor the steam generator;

FIG. 9 is a partial elevation illustrating the lower drum and itssupports;

FIG. 10 is a side elevation of the boiler bank section of the steamgenerator; and

FIG. 11 is an enlarged partial view of the wall structure of FIG. 5.

Referring now to the drawings there is shown a compact, bottom supportedsteam generator unit 10 having enclosing front, rear and opposed sidewalls, 12, 14 and 16 respectively, defining a furnace portion 18 and aboiler bank portion 20 separated by a gas impervious barrier or baffle22. The boiler bank portion 20 includes lower and upper drums, 24 and26, that are parallelly disposed and that extend between the side walls16 of the unit and a bank of heat exchanger tubes 28 interconnecting thedrums in fluid circulation. The boiler bank tubes 28 are arranged suchthat the rear row 28A forms the generator rear wall 14 and the outer endrows 28B are aligned with the furnace side walls 16 thereby forming awelded enclosure generally having the shape of a rectangular prism. Thefurnace 18 and boiler bank 20 are mutually connected for gas circulationby a gas pass 30 formed between the upper end of the gas bafiie 22 andthe roof 38 within which is positioned tubes forming a superheater 32.

In accordance with the invention, as shown in FIG. 5, the entireperiphery of the unit is formed of continuous, Welded wall construction.By this is meant that the enclosing walls or perimetric surfaces of theunit are all constructed of tubular barriers, typical sections of whichare shown in FIGS. 4, 5, 6, comprising spaced tubes 34 having metallicstrips or bars 36 fitted and welded therebetween to form a continuousgas impervious enclosure. The tubes 34, which have a 3 inch CD. aretypically spaced spacedly arranged in side-by-side relation on 4 inchcenters with a metallic filler or bar 36 interposed between and weldedto adjacent tubes. The filler material is required to be of sufiicientthickness to withstand the gas pressure within the unit. A metal barhaving a thickness of approximately inch is deemed sufiicient for thispurpose in the disclosed embodiment. As an alternative, the Welded wallconstruction can comprise a plurality of aligned tubes havinglongitudinally extending diametral fins that are arranged in abuttingside-by-side relation and joined by a continuous longitudinal weld.

With reference to FIG. 1, the furnace 18 is enclosed on three sides byfront wall 12, roof 38 and floor 40. The roof 38 and floor 40 are formedby the leg segments of parallel C-shaped tubes that extend laterallyfrom the upper drum 26 and lower drum 24 respectively, the verticallyelongated bight of which tubes form the front wall 12. Spaces 39 areprovided between adjacent tubes in the roof 38 to accommodate thepassage of superheater inlet and outlet connector lines 42 and 44. Thefurnace enclosure is completed by side walls 16 that comprise aplurality of vertically extending tubes joined at their ends forparallel flow by upper headers 46 and lower headers 48. Supply tubes 50(FIG. 6) connect the lower headers 48 to lower drum 24 and relief tubes52 (FIG. 7) that are similarly connected join the upper headers 46 tothe upper drum 26.

Thermal insulation 54 in the form of mineral wool or the like is appliedto the outer surface of the generator walls being attached thereto asshown in FIG. 4 by means of impaling pins 56 or any other convenientmeans. Preformed lagging 58 comprising a thin metallic material such assteel or aluminum covers the insulation in order to enhance theappearance of the unit and also to protect the insulation against theeffect of environmental elements.

Burners 60 are mounted by appropriate burner mounts in the lower portionof the front wall 16 for generating combustion gases within the furnace18. These gases are caused to flow from the furnace 18 over thesuperheater tubes in gas pass 30 into the boiler bank portion 20 whererefractory bafiies 62 suitably attached to the tubes 28 direct the gaseslaterally across the tubes before they exit through an opening 64located at the bottom of the boiler bank.

As shown, a regenerative air heater 66 having a gas inlet 68communicating with the opening 64 is located at the rear of the unit.The air outlet 70 of the air heater 66 communicates with an air plenumchamber 72 formed beneath the furnace floor 40 the latter supplying airto a burner windbox 74 that surrounds the burners 60.

The gas baffle 22 that separates the furnace 18 from the boiler bank 20comprises a row of parallel tubes 22A (FIG. positioned forward of thefront row of boiler bank tubes 28. These tubes 22A are of welded wallconstruction throughout the portion of their length indicated by thefiller strip 36. They extend the full height of the unit connecting attheir lower ends to lower drum 24 and at their upper ends to upper drum26. As shown, the gas baffle tubes 22A emanate laterally from the lowerdrum 24, extending vertically through the lower portion of the furnace18 and then are laterally offset below, but closely adjacent, the lowerends of the superheater tubes 32 thus forming a baffie nose 76 which iseffective to protect the superheater tubes against exposure to theradiant heat in the furnace. The tubes 22A thereafter extend to the rearof the superheater 32 and are then vertically offset to extend acrossthe gas pass 30 and connect with the upper drum 26. The weldedconstruction of the bafiie 22 extends from the lower drum 26 to a pointimmediately below the rear of the superheater 32. Through this portionof their length adjacent tubes 22A are connected by metallic bars 36 ormay be of the welded fin type alluded to hereinabove. Across the gaspass 30 the tubes are spaced with alternate tubes, indicated as 22B,being rearwardly and laterally offset so as to provide adequate spacethrough which the gases generated in the furnace 18 can flow to theboiler bank 20.

As best shown in FIGS. 5 and 6 the gas bafile 22 extends across the fullwidth of the generator unit between opposed side walls 16 with theendmost fins or bars 36 in the baffle 22 weldedly attached to each ofthe side walls 16. In this manner gases generated by burners 60 areprevented from flowing directly into the boiler bank 20 but instead aredirected upwardly by means of the sloping leg 78 that forms a portion ofthe nose bafi le 76 toward the upper front corner of the furnace 18where a turn is made by the gases and thence they flow through gas pass30 and into boiler bank 20.

By weldedly attaching the gas bafile 22 to the side Walls 16 theunsupported length of the side walls is considerably reduced therebyserving to render the generator more rigid in its construction. Thisstrengthening of the unit thus permits the elimination of expensiveexternal structural steel supporting members and enables the generatorto be completely bottom supported requiring the minimum amount offooting supports. The bottom support arrangement employed in thedisclosed unit is described with reference to FIGS. 1, and 11. Thearrangement comprises reinforced concrete pedestals 80 and 82 that arepositioned beneath the generator adjacent the four corners thereof.Pedestals 80 are positioned at the rear of the unit and are of a size topermit mounting of lower drum cradle supports 84 and rear supportfootings 86 while the forward pedestals 82 are somewhat smaller in thatthey need only mount the forward support footings 88. While the rearsupport footings 86 are not, in fact, necessary in the support of theassembled generator since the weight of the unit in this area isadequately supported by the cradle supports 84, they are found to beuseful in the erection of the unit serving to support the side walls 16during the erection period and for this reason are included in thearrangement. The lower drum cradle supports 84 comprise drum cradles 90mounted on rear pedestals 80. The drum cradles are positioned adjacentthe ends of the lower drum 24 which rests therein being rigidly attachedthereto by means of welding. The drum cradles 90 are each mounte-d upona base plate 94 which is slidably positioned atop a pedestal plate 96that is fixedly attached to the pedestal 80. Lateral stop members 98 arefastened to the plates 96 so as to limit the lateral movement of thecradle supports 84 during expansion of the generator. In this manner thepoint of zero expansion in the generator is substantially fixed at thepoint indicated as O which is substantially the axial midpoint of thedrum 24. The stops 98 are sufficiently spaced from the edges of thepedestal plate 96 to adequately accommodate lateral expansion of theunit in one direction. Their purpose, however, is to limit the expansionof one end of the drum should the other end be prevented from expandingas by its associated cradle base plate 94 being bound upon theassociated pedestal plate 96 and therefore unable to move. Should thisoccur the expandable end of the drum will move until the associatedcradle base plate 94 engages the stop member 98 at which time theexpansion force created will be in the other direction and sufficient toovercome the friction between the base plate 94 and pedestal plate 96associated with the other end of the drum so as to establish movement atthat end and thereby maintain the point of zero expansion at the point0.

Each support footing 86 and 88 comprises a short, cylindrical, verticalcolumn 100 which is rigidly attached as by means of welding to theunderside of the lower headers 48. The column 100 is fixedly mountedupon a footing base 102 which in turn is slidably mounted atop thepedestals 62 and 64 upon plates 104. As shown in FIG. 11 each of thefootings 86 and 88 is radially oriented with respect to the point 0,such orientation being effected by means of brackets 106 provided oneach of the footing plates 104 to engage the edges of the associatedfooting base 102 and thereby limit movement of the footings to thatindicated by the radial lines. The footings 86 and 88 therefore serve tosupport the unit and to accommodate thermal expansion and contractionduring periods of heating and cooling of the generator.

The operation of the herein disclosed unit is as follows. A forced draftfan (not shown) is located at some convenient point near the air inletof air heater 66. This fan will draw the volume of air necessary forcomplete combustion of the fuel and develop sufficient pressure toovercome all air and gas side resistances in the unit. The path of airfrom the forced draft fan is through the air heater 66 and into theplenum chamber 72 formed between the concrete slab upon which thegenerator rests and the furnace floor 40. In the plenum chamber 72 airis distributed uniformly across the width of the unit before enteringthe burner wind box 74. Because of the use of the disclosed plenumchamber 72 the need for external duct work in the unit is minimized. Theburners 60 distribute finely atomized fuel particles within theturbulent air stream and combustion of the fuel-air mixture occurswithin the furnace 18. The combustion gases thus generated are directedagainst the gas bafile 22 and directed upwardly and then through thesuperheater 32 located in the gas pass 30 and thence into the boilerbank 20 where they are directed laterally across the boiler bank tubes28 in three passes formed by refractory bafiies 62 before leavingthrough the outlet opening 64 provided at the lower end of the boilerbank 20 in the rear wall 14. The gases then pass into the gas inlet duct68 of the air heater 66 before being discharged through a stack (notshown). Vaporizable fluid in the form of water or the like is suppliedto the upper drum 26 from which it is uniformly distributed through therelatively cooler downcomer tubes 28 at the rear of the boiler bank 20to the lower drum 24. From the lower drum 24 the water is uniformlydistributed to the various boiler circuits and furnace steaming circuitsby means of supply tubes 48. The density of the steamwater mixture inthe circuits is less than the density of the solid water in the boilerdowncomer tubes thereby creating the potential needed to circulate thefluid needed within the system. All of the steaming circuits terminatein the upper drum 26 where the steam is collected, separated anddischarged into the superheater 32 by means of the connector line 42where the mixture is heated to the final temperature and thencedelivered to the plant piping through an outlet connection 44.

It is contemplated by this invention to form the entire generatorenclosure of welded wall construction which eliminates the need forseparate skin casing as had heretofore been required in the constructionof generators of this type. This elimination of heavy skin casing aroundthe steam generator results in a substantial reduction in generatorcost. The welded wall construction is responsible for a furtherreduction in cost in that it provides in the structure a rigidity thatpermits the use of floor supports for mounting the unit for expansionand contraction instead of heavy external support beams.

It is also contemplated to form a substantial portion of the generatorenclosure as shop-assembled panels. As best illustrated with referenceto FIGS. 2 and 3 the units front, rear and side walls 12, 14 and 16 aswell as the roof 38 and floor 40 are constructed in this manner. Onlythe outer end rows 28B of the boiler bank tubes are not formed ofpanels. These tubes are finned tubes (note FIG. that are erected afterthe several rows of boiler bank tubes 28 have been assembled. Inerecting the tubes 28B, the fins 52 are aligned in abutting relation anda field Weld is applied to connect the fins and form a gas impervioussurface. Plates are fitted and welded in the voids formed by thenon-linearity of the tubes 28B adjacent the drums so as to complete theenclosure in this portion of the unit.

Constructing the steam generator out of preformed shop-assembled panelsis advantageous for several reasons. Firstly, by fabricating the panelsin the shop all welds can be heat treated and thereby being renderedmore uniform and stronger than field welds. Also, by joining the tubesin the form of panels the number of separate structural members thatmust be transported and erected is considerably reduced therebyresulting in a substantial reduction in the cost of material handlingand erection. Moreover, the use of panels that are preengineered and ofstandardized dimensions permits a flexibility of design that requiresless engineering and is therefore less expensive. Steam generatorproportions, which vary from 11 feet to 26 feet deep, 8 feet to 28 feetwide and in three increments of height to suit drum center variables of28 feet, 30 feet and 32 feet are constructed of these standardizedpanels. For example the steam generator shown in FIGURE 2 may be madeless deep by eliminating the side wall panel indicated as C. Similarlythe unit could be made wider by the addition of roof, front wall andfloor panels, E, G and J, as Well as appropriate rear wall panels.Therefore, by the use of panel construction a steam generator employinga modular design concept can be adopted.

While the illustrated and described steam generator unit is a preferredembodiment of the present inventive concept it is to be understood thatthe present description is intended merely to be illustrative and is inno way intended to restrict said inventive concept and that variationsand modifications may be made therein without departing from the scopeof the invention.

What is claimed is:

1. A floor supported steam generator comprising rectangularly disposedfront, rear and side walls including spaced upright tubes to define afurnace and a boiler bank disposed in side-by-side relation and eachextending coextensively traversely the entire width of said steamgenerator; said boiler bank including an upper steam drum,

6 a lower water drum and a plurality of rows of spaced upright tubesconnecting said drums; a row of spaced, continuous C-shaped tubesconnecting said drums, said C- shaped tubes having relatively long upperand lower leg segments extending later-ally from each of said drums todefine the floor and roof of said steam generator and the bight of saidC-shaped tubes forming the front wall thereof; metallic fillersufliciently rigid to contain combustion gases within said steamgenerator welded to and between the adjacent C-sh-aped tubes and thetubes forming the side and rear Walls of the generator so as to renderthe perimetric surfaces thereof gas tight; a second row of upwardlyextending spaced tubes positioned between and separating said furnaceand boiler bank and connecting said drums; gas impervious metallicfiller welded to and between the tubes of said second row and betweenthe end-most tubes thereof and said side walls to form a partitionseparating said furnace and said boiler bank and to rigidify said sidewalls intermediate their ends, said metallic filler extending along saidtubes from said lower drum to a level spaced from said roof; space meansbetween the tubes of said second row above said level establishinggaseous communication between said furnace and said boiler bank; andsupport means engaging the bottom of said steam generator for floorsupport thereof.

2. A floor supprted steam generator comprising rectangularly disposedfront, rear and side walls including spaced upright tubes to define afurnace and a boiler bank disposed in side-by-side relation and eachextending coextensively traversely the entire width of said steamgenerator; said boiler bank including an upper steam drum, a lower waterdrum and a plurality of parallel rows of spaced upright tubes connectingsaid drums; a row of spaced continuous C-shaped tubes connecting saiddrums, said C-shaped tubes having relatively long upper and lower legsegments extending laterally from each of said drums to define the floorand roof of said steam generator, and the bight of said C-shaped tubesforming the front wall thereof; metallic filler sufiiciently rigid tocontain combustion gases within said steam generator welded to andbetween adjacent C-shaped tubes and the tubes forming said side and rearwalls so as to render the perimetric surfaces of said generator gastight; a second row of spaced upright tubes connecting said drums, saidrow of tubes being laterally extensive across the width of the steamgenerator intermediate said front wall and said boiler bank; the tubesof said second row being offset forwardly and rearwardly intermediatethe height thereof to form a nose baffle extending forwardly toward butspaced from said front wall; gas impervious metallic filler welded toand between the tubes of said second row and between the end-most tubesthereof and said side Walls to form a partition separating said furnaceand said boiler bank and to rigidity said side walls intermediate theirends, said metallic filler extending along said tubes from said lowerwater drum to a level above said nose bafile but spaced from said roof;space means between the tubes of said second row above said metallicfiller establishing gaseous communication between said furnace and saidboiler bank; and support means engaging the bottom of said steamgenerator for floor support thereof.

3. A floor supported steam generator comprising rectangularly disposedfront, rear and side walls including spaced upright tubes to define afurnace and a boiler bank disposed in side-by-side relation and eachextending coextensively traversely the entire width of said steamgenerator; said boiler bank including an upper steam drum, a lower Waterdrum and a plurality of parallel rows of spaced upright tubes connectingsaid drums; a row of spaced, continuous C-shaped tubes connecting saiddrums, said C-shaped tubes having relatively long upper and lower legsegments extending laterally from each of said drums to define the floorand roof of said steam generator, and the bight of said C-shaped tubesforming the front wall thereof; metallic filler sutficiently rigid tocontain combustion gases within said steam generator welded to andbetween adjacent C-shaped tubes and the tubes forming said side and rearwalls so as to render the perimetric surfaces of said generator gastight; a second row of spaced upright tubes connecting said drums, saidrow of tubes being laterally extensive across the width of the steamgenerator intermediate said front wall and said boiler bank; the tubesof said second row being offset forwardly and rearwardly intermediatethe height thereof to form a nose baffie extending forwardly toward butspaced from said front wall; gas impervious metallic filler welded toand between the tubes of said second row and between the end-most tubesthereof and said side walls to form a partition separating said furnaceand said boiler bank and to rigidify said side walls intermediate theirends, said metallic filler extending along said tubes from said lowerwater drum to a level above said nose bafiie but spaced from said roof;space means between the tubes of said second row above said metallicfiller establishing gaseous communication between said furnace and saidboiler bank; and floor mounted support means engaging the bottom of saidsteam generator solely at substantially the corners thereof for floorsupporting said generator. v

4. A floor supported steam generator comprising rectangularly disposedfront, rear and side walls including spaced upright tubes to define afurnace and a boiler bank disposed in side-by-side .relation and eachextending coextensively traversely the entire width of said steamgenerato-r; said boiler bank'including an upper steam drum;

extending transversely between said sidewalls, a lower water drumparallel to but spaced from said stearn drum, and a plurality ofparallel rows of spaced upright tubes connecting said drums;'a row ofspaced continuous C- shaped tubes connecting said drums, said C-shapedtubes having relatively long upper and lower leg segments extendinglaterally from each of said drums to define the floor and roof of saidsteam generator, and the bight of said C-shaped tubes forming the frontwall thereof; metallic filler sufliciently rigid to contain combustiongases within said steam generator welded to and between adjacentC-shaped tubes and the tubes forming said side and rear walls so as torender the perimetric surfaces of said generator gas tight; a second rowof spaced, upright tubes connecting said drums, said row of tubes beinglaterally extensive across the width of the steam generator for- "wardlyof said boiler bank but spaced from said front 'wall; the tubes of saidsecond row having a substantially vertical lower portion and beingoffset forwardly and said metallic filler establishing gaseouscommunication between said furnace and said boiler bank; burner meansfor directing combustion gases through said front wall -dire-ctlyopposite and normal to said vertical portion of said partition;superheater means including spaced, parallel rows of U-shaped tubesdepending from said roof and positioned above said nose baflle andrearwardly thereof whereby said nose bafiie shields the bends of saidU-shaped tubes from the radiant heat of said burners; and support meansengaging the bottom of said steam generator for floor support thereof.

5 A floor supported steam generator comprising recrearwardlythereaboveto form a nose baffle spaced from said roof and extendingforwardlytoward said front wall;

8 tangularly disposed front, rear and side walls including spacedupright tubes to define a furnace and a boiler bank disposed inside-by-side relation and each extending co-extensively traversely theentire width of said steam generator; said boiler bank including anupper steam drum extending, transversely between said side walls, alower water drum parallel to but spaced from said steam drum, and aplurality of parallel rows of spaced upright tubes connecting saiddrums; .a row of spaced, continuous C-shaped tubes connecting saiddrums, said C- shaped tubes having relatively long upper and lower legsegments extending laterally from each of said drums to define the floorand roof of said steam generator, and the bight of said C-shaped tubesforming the front wall thereof; said side walls including verticallyparallel tubes; horizontal upper and lower header means extending fromsaid front wall to said boiler bank uniting said vertical tubes in fluidcirculation; tubular means connecting said header means and theirassociated drums; metallic filler sufl'iciently rigid to containcombustion gases Within said steam generator welded to and between saidC-shaped tubes and the tubes forming said side and rear walls so as torender theperimetric surfaces of said generator gas tight; a second rowof spaced, upright tubes connecting saidjdrums, said row of tubes beinglaterally extensive across the width of the steam generator forwardly ofsaid. boiler bank but spaced from said front wall; the tubes ofsaidsecondrow having a substantially vertical lower portion and being offsetforwardly and rearwardly thereabove to form .a nose baffle spaced fromsaid roof and having its apex extending forwardly toward said frontwall; gas impervious metallic filler welded to and between the tubes ofsaid second r-ow and between the end-most tubes thereof and said sidewalls to form a partition separating said furnace and said boiler bankand to rigidify said side walls intermediate their ends, said metallicfille extending along said tubes from said lower water drum to a levelabove saidnose baffle apex but spaced from said roof; space meansbetween the tubes of said second row above said metallic fillerestablishing gaseous communication between said furnace and said boilerbank; burner means for directing combustion gases through said frontwall directly opposite and normal to said vertical portion of saidpartition; superheater means including spaced, parallel rows of U-shapedtubes depending from said roof and having their bends located above saidnose baflle and rearwardly of its apex therebybeing shielded from theradiant heat of s'aid'burners; and floor mounted support meanspositioned solely at the corners of said" steam generator includingspaced drum saddle means engaging said water drum at its ends and spacedcolumn support means engaging said lower header means at its ends forfloor supporting said steam generator.

References Cited by the Examiner UNITED STATES PATENTS 2,293,833 8/42Kuhner et al. 122-336 2,655,238 10/53 Langvand 122-494 2,749,887 6/56Olsen 122-494 2,762,635 9/56 Lorber 122-510 2,774,340 12/56 Jankowski122-510 2,856,907 10/58 Koch 122-478 2,900,174 8/59 Deitrick 122-4763,003,482 10/61 Hamilton et al. 122-478 3,012,548 12/61 Guszmann 122-494PERCY L. PATRICK, Primary Exiaminer.

KENNETH W. SPRAGUE, Examiner.

1. A FLOOR SUPPORTED STEAM GENERATOR COMPRISING RECTANGULARLY DISPOSEDFRONT, REAR AND SIDE WALLS INCLUDING SPACED UPRIGHT TUBES TO DEFINE ASURNACE AND A BOILER BANK DISPOSED IN SIDE-BY-SIDE RELATION AND EACHEXTENDING COEXTENSIVELY TRAVERSELY THE ENTIRE WIDTH OF SAID STEAMGENERATOR; SAID BOILER BANK INCLUDING AN UPPER STEAM DRUM, A LOWER WATERDRUM AND A PLURALITY OF ROWS OF SPACED UPRIGHT TUBES CONNECTING SAIDDRUMS; A ROW OF SAPCED, CONTINUOUS C-SHAPED TUBES CONNECTING SAID DRUMS,SAID CSHAPED TUBES HAVING RELATIVELY LONG UPPER AND LOWER LEG SEGMENTSEXTENDING LATERALLY FROM EACH OF SAID DRUMS TO DEFINE THE FLOOR AND ROOFOF SAID STEAM GENERATOR AND THE BIGHT OF SAID C-SHAPED TUBES FORMING THEFRONT WALL THEREOF; METALLIC FILLER SUFFICIENTLY RIGID TO CONTAINCOMBUSTION GASES WITHIN SAID STEAM GENERATOR WELDED TO AND BETWEEN THEADJACENT C-SHAPED TUBES AND THE TUBES FORMING THE SIDE AND REAR WALLS OFTHE GENERATOR SO AS TO RENDER THE PERIMETRIC SURFACES THEREOF GAS GITHT;A SECOND ROW OF UPWARDLY EXTENDING SPACED TUBES POSITIONED BETWEEN ANDSEPARATING SAID FURNANCE AND BOILER BANK AND CONNECTING SAND DRUMS, GASIMPERVIOUS METALLIC FILLER WELDED TO AND BETWEEN THE TUBES OF SAIDSECOND ROW AND BETWEEN THE END-MOST TUBES THEREOF AND SAID SIDE WALLS TOFORM A PARTITION SEPARATING SAID FURNACE AND SAID BOILER BANK AND TORIGIDIFY SAID SIDE WALLS INTERMEDIATE THEIR ENDS, SAID METALLIC FILLEREXTENDING ALONG SAID TUBES FROM SAID LOWER DRUM TO A LEVEL SPACED FROMSAID ROOF; SAPCE MEANS BETWEEN THE TUBES OF SAID SECOND ROW ABOVE SAIDLEVEL ESTABLISHING GASEOUS COMMUNICATION BETWEEN SAID FURNACE AND SAIDBOILER BANK; AND SUPPORT MEANS ENGAGING THE BOTTOM OF SAID STEAMGENERATOR FOR FLOOR SUPPORT THEREOF.